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Resolve an Await function if it takes more than x seconds in Javascript / Node.js

Time:08-27

I have an await function() which waits for an external API. Usually, these APIs take 600ms to return data. But sometimes it's taking around 10 seconds. So how do I write a function so that if it takes more than 1 second, then break that function and resolve anyway (don’t wait for the API)

Here's the main function code which calls the API.

console.log("Before Await");

await fetchExternalAPI("data");

console.log("Continue if success or takes more than x seconds");

The actual function:

const fetch = require('node-fetch');

module.exports = async function fetchExternalAPI(data) {

    try {
        const response = await fetch("https://www.example.com/api/log", {
            method: "POST",
            headers: { "Content-Type": "application/json" },
            body: JSON.stringify(data)
        });

        const returnData = await response.json();
        console.log("Response: "   JSON.stringify(returnData))
        return returnData
    }
    catch (e) {
        console.log("Error: "   e)
        return e
    } 
}

I want to return success fo the above function

  1. if fetch is success
  2. or if exceeded more than x seconds

Both should return success no matter the real output.

CodePudding user response:

You can use AbortController to abort the fetch method, inside a setTimeout with 1sec, and if the fetch resolved before the setTimeout callback execute, then clearTimeout

const fetch = require('node-fetch');

module.exports = async function fetchExternalAPI(data) {

    try {
        let controller = new AbortController();
        let timeId = setTimeout(() => {
           controller.abort()
 
        }, 1000)
        const response = await fetch("https://www.example.com/api/log", {
            method: "POST",
            headers: { "Content-Type": "application/json" },
            body: JSON.stringify(data)
            signal: controller.signal
        });
        clearTimeout(timeId)
        const returnData = await response.json();
        console.log("Response: "   JSON.stringify(returnData))
        return returnData
    }
    catch (e) {
        console.log("Error: "   e)
        return e
    } 
}

CodePudding user response:

I think you need to use Axios.

npm i axios 

than in body you have one property timeout.

const instance = await axios.create({
 baseURL: 'https://some-domain.com/api/',
  timeout: 1000,
  headers: {'X-Custom-Header': 'foobar'}
});

CodePudding user response:

You can add a promise in your call to resolve on time and reject if too long. The following code has not been tested but that's the idea

  const fetch = require('node-fetch');

  module.exports = async function fetchExternalAPI(data) {

    try {
      const response = await fetch("https://www.example.com/api/log", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(data)
      });

      await new Promise((resolve, reject) => {
        setTimeout(reject, 50000));
        resolve();
      }).then(() => {
        const returnData = await response.json();
        console.log("Response: "   JSON.stringify(returnData))
        return returnData
      }).catch(() => {
        return 'Took too long';
      }));
    }
    catch (e) {
      console.log("Error: "   e)
      return e
    } 
  }
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